Taking into account that the anime pretty much sucks, it would be good if they included Vergil or anyone else as long as it becomes a bit better. I don't see why it should remain cannon, it just shows Dante's daily routine. Don't get me wrong, I like it, it has some good and funny moments. I'm just a bit disappointed since it's DMC after all.
He's bored out of his mind, all devils die after a few minutes - although that guy in Episode 8 knew Sparda, so that was slightly better - he's got debts because he has as much luck as Spider-man and he eats pizza and strawberry sundae all day. Yeah ok, we know Dante does some of those, but I don't see why they should make an anime based on that.
The good thing is that episodes "start" having some plot -crappy though.
So definitely Vergil/Nelo Angelo or whoever it is SHOULD appear if that would make the anime a bit more interesting.